Sugar, Free radicals and UV – why are these ageing us?

Sugar, Free radicals, UV                   

Why are they ageing us? 

Two of the biggest assaults on skin are glycation and oxidisation.  Oxidisation is primarily from sun damage whereas Glycation is from diet.  Glycation is basically when a sugar and protein (collagen and elastin) meet, and the result is an end product called (AGES).  AGES result in tissue atrophy and loss of function.  AGES affect the skins protein fibres as well as the dermal glycoproteins (fibrillin-1) and glycosaminoglycans which affects cell growth, fibroblast production, enzymatic activity etc. Glycation is always occurring, however, due to the buildup of damage in underlying skin structures it can take time to manifest visually.

What does a glycated skin look like?

A glycated skin has tissue stiffening and reduced elasticity which in turn increases appearance of wrinkles and sagging.  Glycation prevents the keratinocytes from migrating up through the epidermis which can have an impact on wound healing and the cells' ability to generate what it needs to make to aid in proper cross linking of collagen.  The skins barrier is affected with less epidermal lipids and ceramides being produced. The heavily glycated rigid collagen fibres have also been found to cause collapse of fibroblast cells which produce organised collagen, so further breakdown in skin.  UV exposure and AGE formation also increases MMP-1 which is an enzyme that breaks down collagen.

What happens?

Glucose and Fructose attach themselves to protein molecules which eventually become irreversible. Collagen needs flexibility but sticky glucose turns it stiff, and skin becomes yellowed.    AGEs will also affect the elastin and cause sagging. AGEs are present in the skin and then with UVA damage (oxidisation) it becomes amplified. We do have enzymes found naturally in our body that will help break down the methylglyoxal (a by-product in the glycation process) but we lose these enzymes as we age.   Diabetics who already have a difficult problem in processing the glucose find their skin more prone to glycation issues such as neuropathy (nerve damage) and scleroderma (auto immune disease).

Unfortunately, it’s not just the skin that is affected by AGES, but they can also lead to cardiovascular disease and the development of Alzheimers.  This is built on the fact that we already know AGES are responsible for cataracts, macular degeneration, diabetic neuropathy, artery disease and skin ulcers.

Glycation end products wouldn’t be so bad if they just floated around in the blood, but they are attracted to cells by RAGES, which are receptors on cell walls that are responsible for initiating the inflammatory process. From here, cellular inflammation occurs which is a major factor in ageing as well as other inflammatory diseases such as asthma, arthritis, Alzheimers, neuropathy, vascular and loss of dermal volume.

Latest research has now only recently found that the glycation process also plays a role in pigmentation the melanocyte cells also have RAGE receptors, and AGEs trigger an increase in tyrosinase which is an enzyme responsible in the second step of pigmentation and MITF which is a master regulator of pigmentary enzymes. When keratinocytes are exposed to UV there is found to be an increase of AGE secretion. Two of the AGES are found to interfere with biological substances including DNA and can induce strand breakage and DNA cross linking causing inactivation of DNA segments.

Links to Diet

To further drive home the message about how damaging sugar can be, tests performed on keratinocyte cells with glucose solution changed young cells to old, near death and dysfunctional cells in just three days, leading to opinion that high sugar diets will speed up the ageing process.

The way we cook our food also plays a huge part.  Food cooked at high and fast temperatures produce AGEs in the meat proteins that we then ingest.  Diets that include slow cooked and water-based cooking has proven to show a reduced number of inflammatory markers such as interleukin-6, C-reactive protein and Tumor Necrosis factor-alpha.

Herbs and spices such as cinnamon, cloves, allspice and oregano, have been shown to inhibit the production of AGEs.  Green tea, Garlic and Ginger, and amino acids such as taurine, carnosine, carnitine are all also said to inhibit AGE production.

Avoid cigarettes as they contain high levels of glycotoxins that get into the blood stream and induce the formation of AGES and are of course the major factor in lung cancer.  Cigarettes induce AGES which harm the skin in the same way as well as reducing oxygen supply.  Finally EXERCISE because about 70% of blood glucose is consumed by muscle which means any weight bearing exercise will help.

Can cosmeceuticals help?

The bad news is skincare will not make much of an impact in treatment of glycation without a change of diet and exercise.  However, in skincare we can look for ingredients such as tocopherol, kombucha, white willow, licorice root, horse chestnut, olive, green tea, beta glucan, Aminoguanidine, blueberry extract, Mangosteen, Chamomile, hawthorn berry, Olive leaf, dokudami, blueberries, pomegranate extract, carnosine, grape leaf and of course SUNSCREEN.  Vit b6 and carnosine have also shown evidence in inhibiting AGES.  ZINC may help as it assists the hormone insulin in regulating blood sugar levels.  It also targets two proteins that are involved with the degradation of collagen by interceding when collagen is exposed to UV, and it activates DNA processes allowing it to repair and self-correct.

Laboratories already use autofluorescence readers to detect AGES and hopefully it won’t be long before we can look forward to this technology being readily available in salons too.  There are drugs available to reduce glycation that are primarily hypoglycemic in nature and used to treat diabetics.

Sources Terry Everitt APJ volume 25 (2015) and APJ 2016, Tina Viney APJ, Jacine Greenwood Drummond – APJ, DMK, AACDS